I found some more info about this, from the blog, The Playlist
With Warner Bros. moving ahead with their big budget "Wizard Of Oz" prequel, "Oz The Great And Powerful" with Sam Raimi in the director's chair and starring Robert Downey Jr., it looks like they will be beaten to the punch by indie auteurs Michael and Mark Polish.
A mysterious teaser titled "Oz" has hit YouTube with the description "Polish Brothers' OZ, based on the beloved children's classic by L. Frank Baum. Hitting screens everywhere in 2011." The project doesn't exist on IMDB and appears to be something the directors of "Twin Falls Idaho," "Northfork" and "The Astronaut Farmer" have been working on in secret. The brief teaser appears to indicate this film will be a prequel of sorts as well, with a very young Dorothy walking with the Cowardly Lion down a hallway. And that's about it.